1. Field of the Invention
The present invention relates to an apparatus for ventilating a compartment of a conveyance typified by, for example, a railway vehicle.
2. Related Art Statement
As a typical conventional technology, there are a ventilating apparatus having relaxation means for changing the ventilation passage connected to an air blower and disclosed in Japanese Patent Laid-Open No. 63-199170, a ventilating apparatus having a Roots fan for sucking/exhausting air and disclosed in Japanese Patent Laid-Open No. 64-18766, and a structure having a plurality of pairs each of which is composed of an air blowing opening and an air suction opening formed in the roof surface and arranged in such a manner that the plurality of the pairs are combined with an exclusive air conditioning apparatus. Then, a typical example of the conventional structures will now be described with reference to FIG. 11 which is a plan view from which a portion is omitted.
Referring to FIG. 11, a suction means 2 is disposed in the upper portion of a railway vehicle 1, for example, in a portion between the ceiling and the roof. Outside air introduced by the suction means 2 is branched into two sections after it has passed through an air passage 3. One of the branched air flows is supplied to an air conditioning means 4 via an air passage 3a, while the residual air flow is supplied to another air conditioning means 9 via an air passage 3b.
The air conditioning means 4 and 9 are also respectively supplied with circulated air which has flowed through circulation ports 5 and 14 and circulation ports 10 and 15 formed at arbitrary positions of the ceiling via air passages 6 and 16 and air passages 11 and 17.
Circulated air and fresh air introduced from the outside of the vehicle are mixed with each other by the air conditioning means 4 and 9 so as to be conditioned with each other, and they are supplied to corresponding muffling means 7 and 13 and introduced into a duct 8.
The duct 8 uniformly introduces conditioned air into the compartment and also supplies conditioned air to required portions, for example, a driver's cabin and a lavatory.
Air circulated in the compartment is, via an individual duct, introduced into an exhaust means through exhaust ports formed in the floor, and is exhausted to the outside of the vehicle through this exhaust means.
FIG. 12 is a schematic cross sectional view taken along a cross sectional line XII--XII of FIG. 11. The air passages 3a and 3b are formed by partitioning the inside portion of an outer surface 18 of a vehicle body 1 by partition 19.
FIG. 13 is a cross sectional view taken along a cross sectional line XIII--XIII of FIG. 11. The air passages 3b and 12 are formed in such a manner that they are partitioned by a partition member 20.
FIG. 14 is a cross sectional view taken along a cross sectional line XIV--XIV of FIG. 11. In this portion, only the air passage 3b is formed.
The structure thus arranged encounters a problem that odor from a lavatory can be mixed with the circulating air in the case where a lavatory is located in the vehicle body. In order to overcome the aforesaid problem, an exclusive exhaust means and an exhaust passage for the lavatory are individually provided in the aforesaid conventional structure. In this case, the number of the facilities and equipment cannot be decreased, causing the structure to be complicated and causing the cost to be enlarged.
Furthermore, the configuration of the facilities is too complicated as shown in FIGS. 11 to 14 and therefore the construction cannot be easily established. Therefore, the conventional structure cannot be manufactured easily.
What is worse, it is difficult for each of the air passages to keep a required cross sectional area due to a limitation of the installation space. Therefore, a problem of noise usually takes place due to the cooling and heating performance, the air quantity and the wind velocity.
Since the conventional structure is composed of a single ventilation system in the overall vehicle, another problem arises in that the overall function is stopped when the ventilating apparatus becomes defective. Furthermore, the compartment cannot be divided into smoking inhibited seats and permitted seats because the circulated air is not separated. Furthermore, space available for the air ducts is normally very restricted, so the cross-sectional area of each duct is very limited. Consequently, the air conditioning efficiency is reduced when the air flow rate is decreased, and noise caused by the air flow increases when the air flow rate is increased.